Bent something inside the front right caliper... - PeachParts Mercedes-Benz Forum

frankengrant · #1 04-16-2011, 06:29 AM

Did my front brakes tonight and used a long screwdriver to press the piston in, the screwdriver slipped and I bent the inner ring on this part, not sure it is that part, but it looks like the metal one in this picture, like I said, I bent the inner ring of that one, folded a part of the inner circle in on itself:

http://catalog.peachparts.com/ShopByVehicle.epc?q=&yearid=1985@@1985&makeid=63@@Mercedes%2DBenz&modelid=6193%3AED%7C10000135%3AMBC%7C1504@@300D&catid=241658@@Brake&subcatid=241679@@Caliper+Repair+Kit+%2D+Front&applicationid=W0133-1633803@@Caliper Repair Kit - Front&mode=PA
I bent it back as best as I could, but it's not perfect by any means.

I put my brake pads in, they slid in fine, put everything back together, no weird noises when driving, everything stops well.

What is the part that I bent? Is it a big deal? Easy repair?

snookwhaler · #2 04-16-2011, 09:07 AM

It is just the "heat shield".

No worries... Drive on...

vstech · #3 04-16-2011, 09:14 AM

you could have damaged the piston seal. it does two things, one it keeps dust out of the piston, and two it retracts the piston from the disc face after braking... I'd pull it back apart, and inspect it well.

Yak · #4 04-16-2011, 10:26 AM

A properly seated and oriented heat shield is also important for ensuring the pad meets the rotor squarely or with just a hint of leading edge slope. This is needed to minimize and squeal or chatter with the pad.

Best case is no impact at all.

Worst case (assuming an intact dust boot) could be the pad doesn't properly contact the rotor and reduced effectiveness or uneven braking.

It's worth checking out while you're thinking about it. Pad wear or squealing could show up later.

tangofox007 · #5 04-16-2011, 10:49 AM

Quote:

Originally Posted by vstech

you could have damaged the piston seal.

That's a pretty farfetched possibility.

Quote:

Originally Posted by vstech

it does two things, one it keeps dust out of the piston, and two it retracts the piston from the disc face after braking...

Doesn't the seal deserve at least a little credit for keeping all that brake fluid and tons of hydraulic pressure in the right place? I suspect that's a little more significant than "dust control." Which happens to be the job of the dust boot, not the caliper seal.

leathermang · #6 04-16-2011, 10:56 AM

For others watching this..
a Screwdriver is not the proper tool to move the brake pistons back... there are various cheap and effective tools for this procedure...often they look like scissor jacks.. except really small....

bobodaclown · #7 04-16-2011, 11:03 AM

c-clamp and the old pad has worked for me. If you've added fluid to the reservoir between brake pad changes make sure to remove some prior to pushing the caliper back in. Other wise you'll have a big mess. I think it's covered in the repair manual.

vstech · #8 04-16-2011, 11:18 AM

Quote:

Originally Posted by tangofox007

That's a pretty farfetched possibility.

Doesn't the seal deserve at least a little credit for keeping all that brake fluid and tons of hydraulic pressure in the right place? I suspect that's a little more significant than "dust control." Which happens to be the job of the dust boot, not the caliper seal.

... Gee tango, you're grumpy...
I of course meant the dust boot... that is part of the heat shield combo that is likely to have been damaged with his screwdriver...
I was NOT talking about the piston seal that holds back the hydraulic fluid...

vstech · #9 04-16-2011, 11:20 AM

Quote:

Originally Posted by bobodaclown

c-clamp and the old pad has worked for me. If you've added fluid to the reservoir between brake pad changes make sure to remove some prior to pushing the caliper back in. Other wise you'll have a big mess. I think it's covered in the repair manual.

that will work on 87-93 124's but the older and newer cars have opposing piston calipers, and it's difficult to use a c-clamp. they make devices for compressing pistons on these cars.

tangofox007 · #10 04-16-2011, 11:22 AM

Quote:

Originally Posted by vstech

I was NOT talking about the piston seal that holds back the hydraulic fluid...

That happens to be the seal that retracts the piston. The dust boot certainly doesn't do that.

Quote:

Originally Posted by vstech

... Gee tango, you're grumpy...

Misinformation has that affect on me.

frankengrant · #11 04-16-2011, 06:19 PM

About how long would it take me to fix that? Is it a hard job?

vstech · #12 04-16-2011, 08:17 PM

Quote:

Originally Posted by vstech

you could have damaged the piston seal. it does two things, one it keeps dust out of the piston, and two it retracts the piston from the disc face after braking... I'd pull it back apart, and inspect it well.

OK,
lets expound on my slightly off explanation...
the metal shield that got damaged could also have damaged the dust boot around the piston... I was under the impression it was responsible for retracting the piston after braking, but I've been informed that's not what does it, the piston seal does. OK, but the damaged boot, could allow dirt etc to get into the piston seal, causing damage to it...
better tango?